最简单的窗口弹出程序

#include<windows.h>
LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);

int WINAPI WinMain(HINSTANCE hInstance,
       HINSTANCE hPrevInstance,
       PSTR szCmdLine,
       int iCmdShow
       )
{
 static TCHAR szAppName[]=TEXT("HelloWin");
 HWND hwnd;
 MSG msg;
 WNDCLASS wndclass;
 wndclass.style=CS_HREDRAW|CS_VREDRAW;
 wndclass.lpfnWndProc=WndProc;
 wndclass.cbClsExtra=0;
 wndclass.cbWndExtra=0;
 wndclass.hInstance=hInstance;
 wndclass.hIcon=LoadIcon(NULL,IDI_APPLICATION);
 wndclass.hCursor=LoadCursor(NULL,IDC_ARROW);
 wndclass.hbrBackground=(HBRUSH)GetStockObject(WHITE_BRUSH);
 wndclass.lpszMenuName=NULL;
 wndclass.lpszClassName=szAppName;

 if(!RegisterClass(&wndclass))
 {
  MessageBox(NULL,TEXT("程序出错"),TEXT("窗口无法建立"),MB_ICONERROR);
  return 0;
 }

 hwnd=CreateWindow(szAppName,
  TEXT("演示窗口"),
  WS_OVERLAPPEDWINDOW,
  CW_USEDEFAULT,
  CW_USEDEFAULT,
  CW_USEDEFAULT,
  CW_USEDEFAULT,
  NULL,
  NULL,
  hInstance,
  NULL
  );
 ShowWindow(hwnd,SW_SHOWNORMAL);
 UpdateWindow(hwnd);
 while(GetMessage(&msg,NULL,0,0))
 {
  TranslateMessage(&msg);
  DispatchMessage(&msg);
 }
 return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam)
{
 HDC hdc;
 PAINTSTRUCT ps;
 switch(message)
 {
 case WM_CREATE:
  return 0;
 case WM_PAINT:
  hdc=BeginPaint(hwnd,&ps);
  EndPaint(hwnd,&ps);
  return 0;
 case WM_DESTROY:
  PostQuitMessage(0);
  return 0;
 }
 return DefWindowProc(hwnd,message,wParam,lParam);
}